The usage of cold plates for laboratory dissection has been well known for many years. Previously, cold plates generally included a petry dish or plate supported by a receptacle holding ice or dry ice to maintain a specimen sample at a refrigerated temperature during dissection. However, these particular cold plates can not maintain a sample at a frozen temperature of -20.degree. C. or even at a refrigerated temperature somewhat above 0.degree. C. for long periods of time which are necessary when dissecting some samples, such as brain tissue. In addition, the plates are not uniformly cooled, enabling portions of a sample to thaw prematurely before the completion of a dissection experiment. Furthermore, circularly shaped plates also present the problem of premature sample thawing when a sample is positioned near the periphery of the plate due to the difficulty in cooling the peripheral regions of a circular cold plate.
In more recent years, attempts have been made to mount a plate near or on a refrigerated rod to keep a plate at a frozen temperature. However, these plates only cool the region of the plate in contact with the refrigerated rod or coil preventing uniform cooling. Consequently, these plates are provided only in a very small size, and even so the only spot that maintains constant temperature is directly over the rod, with samples on the periphery tending to thaw.
Refrigerated plates, which are generally used in ice boxes and on counter tops have been used for many years to refrigerate or cool foods. For example, U.S. Pat. Nos. 2,640,329 to Ingvardsen and 2,759,339 to Kundert, both show cold plates including an embedded matrix of hollow tubing to circulate a refrigerant delivered from a remote refrigeration unit to cool the plate to a desired temperature. However, these abovementioned patents only disclose cold plates used for cooling food and are not constructed or capable to be utilzed for dissection procedures.
The U.S. Pat. No. 3,832,862 to Ingels, discloses a laboratory refrigeration apparatus which includes an open well type refrigerator unit for specimens. No provision is made for incorporating a dissection cold plate to the refrigeration unit.
Moreover, no prior laboratory dissection plate is known which includes a light source below the plate's cutting surface to illuminate the sample and the plate during dissection at cooled temperatures. No cold plate used for dissection purposes has previously been available which is capable of uniformly cooling the plate to any desired sub-freezing temperatures and which includes a light source to illuminate the working surface of the plate, nor has there been provided a receptable to support the entire refrigerated plate for preventing direct contact with the cold plate by a scientist or technician when in use.